Valves or pumps often include a ball connected to a shaft or stem, where the ball and stem rotate together within a body of the valve or pump. Valves and pumps typically include a seal or packing element and a packing gland between the body and the shaft or stem to limit leaking of the valve or pump. The packing gland is mounted onto the body to compress the seal or packing element within the body with a set of fasteners.
Conventional packing glands are generally composed of rigid metals, such as steel. The rigid packing gland is secured to the valve body so as to provide a compressive force at the packing element. During the life of the valve or pump, the seal or packing element deteriorates over time resulting in leaks as the compressive force applied by the packing gland is reduced due to the deterioration of the seal. Accordingly, conventional steel packing glands require repeated periodic adjustment or tightening to prevent leaking of the valves or pumps. In addition, such conventional packing glands may also require the use of a plurality of springs or spring washers, such as Belleville washers, to provide additional spring action onto the packing gland to provide additional pressure onto the packing assembly to prevent leaking of the valve or pump. The Belleville washers are typically positioned between the packing gland and the heads of bolts that mount the packing gland to the valve body, such that the washers urge the rigid packing gland toward the valve body. However, such arrangement requires additional components and may require tightening of the fasteners as the seal deteriorates.
Thus, there is a desire to provide a packing gland assembly which provides an effective compression force at the seal or packing element and overcomes the shortcomings of the prior art.